Local quenches in frustrated quantum spin chains: global vs. subsystem equilibration

TL;DR

This paper investigates how local quenches affect the equilibration process in frustrated quantum spin chains, revealing diverse statistical behaviors that characterize different equilibration regimes in complex quantum systems.

Contribution

It introduces a comprehensive analysis of equilibration statistics in frustrated quantum spin chains following local quenches, highlighting universal distribution functions as tools for characterization.

Findings

Equilibration statistics vary with quench parameters, showing Gaussian, exponential, or bistable distributions.

Universal functions effectively characterize different time-evolution responses.

The study provides insights into complex equilibration phenomena in interacting quantum systems.

Abstract

We study the equilibration behavior following local quenches, using frustrated quantum spin chains as an example of interacting closed quantum systems. Specifically, we examine the statistics of the time series of the Loschmidt echo, the trace distance of the time-evolved local density matrix to its average state, and the local magnetization. Depending on the quench parameters, the equilibration statistics of these quantities show features of good or poor equilibration, indicated by Gaussian, exponential or bistable distribution functions. These universal functions provide valuable tools to characterize the various time-evolution responses and give insight into the plethora of equilibration phenomena in complex quantum systems.